Primary Outcomes

To evaluate the safety as measured by the number of treatment-emergent and related adverse events as assessed by CTCAE (v4.03).

time frame:
24 weeks

Efficacy as measured by the percentage change in lactate dehydrogenase or LDH levels from baseline to Day 169 during treatment with ALXN1210.

time frame:
24 weeks

Secondary Outcomes

Measure

Time to maximal concentration of ALXN1210 in blood (tmax)

time frame:
24 weeks

Area Under the plasma concentration versus time Curve (AUC) of ALXN1210.

time frame:
24 weeks

Peak Plasma Concentration (Cmax) of ALXN1210.

time frame:
24 weeks

ALXN1210 elimination half-life (t1/2) in blood.

time frame:
24 weeks

Change from baseline in concentration of complement factor 5 (C5). Change from baseline in serum levels of terminal complement activity

time frame:
24 weeks

Development of antibodies against ALXN1210.

time frame:
Up to 128 weeks

Eligibility Criteria

Male or female participants at least 18 years old.

Inclusion Criteria:
1. Male or female ≥ 18 years of age
2. PNH diagnosis confirmed by documented high-sensitivity flow cytometry
3. Documented meningococcal vaccination not more than 3 years prior to dosing
4. Female patients of childbearing potential must use highly effective contraception
starting at screening and continuing until at least 6 months after the last dose of
ALXN1210.
5. Willing and able to give written informed consent and comply with the study visit
schedule
Exclusion Criteria:
1. Treatment with a complement inhibitor at any time
2. Females who are pregnant, breastfeeding or who have a positive pregnancy test at
screening or Day 1
3. Participation in a clinical study within 30 days before initiation of dosing on Day
1, or use of any experimental therapy within 30 days prior to dosing on Day, or
within 5 half lives of the product, whichever is greater
4. History of allergy to excipients of ALXN1210 or known allergy to Chinese hamster
ovary (CHO) cell proteins
5. Inability to comply with study requirements
6. History of any clinically significant cardiac, hepatic, immunologic, pulmonary, or
rheumatoid disease that, in the Investigator's judgment, would preclude participation
7. Other unspecified reasons that, in the opinion of the Investigator or Sponsor, make
the patient unsuitable for enrollment